Process for lowering the pour point of mineral oils



Patented Sept. 22, 1936 PATENT OFFICE PROCESS FOR LOWERING THE POUR POINT OF MINERAL OILS Franz Rudolf Moser, Amsterdam, Netherlands, assignor to Shell Development Company, San Francisco, Calif., a corporation of Delaware No Drawing. Application August 30, 1935, Serial No. 38,576. In the Netherlands October 3, 1934 20 Claims.

This invention relates to a process for manufacturing hydrocarbon oils with a low pour point or cold test or equivalent inspection test, such as lubricating oils, Diesel fuels, fuel oils, etc., and

to a hydrocarbon oil composition having a low pour point.

In accordance with the present invention the pour point, cold test, or equivalent inspection test of such hydrocarbon oils is lowered by the addition to such oils of soaps of the tetravalent form of a metal from the titanium subgroup of Group IV and higher carboxylic acids. Thus, it was found that soaps containing any of the metals of the titanium subgroup, such as zirconium, hafnium and thorium may be employed, but I have obtained best results with titanic soaps, and prefer them to the other soaps.

The titanium soaps can, for example, be prepared by reacting the metallic chloride with the anhydrous carboxylic acid, as described by L. W. Ryan and W. W. Plechner in Ind. Eng. Chem, 26, (1934) p. 909.

The carboxylic acids which are employed in producing the soaps used according to the present invention should contain between ten and thirty','or even more carbon atoms, may be monoor poly-basic, and may be either saturated or not. Thus, I have found fatty acids, such as stearic acid, palmitic acid, oleic acid, linoleic acid, behenic acid, cerotic acid to be particularly suitable. Other examples of carboxylic acids which I have found to be suitable for reaction with the metal chloride to form the desired soaps are: naphthenic acids, such as tetradeca-, hexadecaand nonadeca-naphthenic acids, and -mixtures of naphthenic acids as obtained by extracting petroleum with sodium hydroxide solutions; colophonic acids, such as abietic acid and pimaric acid; oxy-acids, such'as rlcinoleic acid; oxida- 40 tion products of paraffin wax.

Besides'the neutral salts it of the tetravalent metals ofthe titanium subgroup, also basic salts may be used as pour point reducers. Thus, although the theoretical TiOz content of.v titanic 5 tetrastearate is about 6.75%, I have obtained good results when using titanic soaps containing around'9% and even higher amount of TiOz.

The TiOz content should, however, preferably be not over about 13.5%. I have, moreover, found that the best results are obtained when the soap contains four acyl side chains.

Thepour point reducing agents according to the present invention are generally more active than the soaps of bivalent and trivalent metals,

such as zinc oleate and aluminum stearate, which have heretofore been used for this purpose. They have the additional advantage of a comparatively smaller ash content.

In treating hydrocarbon oils with the soaps according to my invention, a small quantity, .usu- 5 ally between 0.02% and 1.0% is added to a waxcontaining oil,"preferably but not necessarily at a temperature at which the wax is wholly or substantially liquid or dissolved in the oil. It should be noted that my invention is not, how- 10 ever, restricted to the use of the aforesaid quantities, since the quantity of soap to be employed in any case will depend upon the decrease in the pour point which it is desired to effect, upon the quantity and nature of the wax present in 15 the oil, and upon the viscosity of the oil. Thus it was found that pour point reducers have a comparatively greater effect on parafiinic oils of low viscosity, and in the case of fuel oils or Diesel fuels amounts as low as 0.01% or lower may often be effective. My invention may, however, be applied also to the treatment of the more viscous hydrocarbon oils, such as cylinder oils and other lubricating oils.

The effect of certain of my soaps on hydrocar-- 25 bon oils is illustrated in the following examples:

Example I Example II 35 An extra heavy neutral oil derived from Pennsylvania and Mid-Continent crudes had a pour point of 10 F. Upon adding 0.5% of titanium stearate (containing 8% TiOz) the pour point was reduced to 0 F. The addition of 1.0% of titanium 40 stearate reduced the pour'point to 5 F.

I claim as my invention:

, l. A low pour point mineral oil composition comprising wax-containing mineral oil and a small quantity of a soap of the tetravalent form 45 of a metal of the titanium subgroup of group IV and a carboxylic acid containing more than nine carbon atoms.

2. The composition according to claim 1 in which the quantity of the soap is between 0.01% 5 and 1.0% of the composition.

3. A low pour point mineral oil composition comprising wax-containing mineral oil and a small quantity of a soap of the tetravalent form of a'metal selected from the group consisting 55 of titanium, hafnium and thorium, and a carboxylic acid containing more than nine carbon atoms.

4. A low pour point mineral oil composition comprising wax-containing mineral oil and a small quantity of a titanic soap of a carboxylic acid containing more than nine carbon atoms.

5. The composition according to claim 4 in which the quantity of the soap is between 0.01%-

and 1.0% of the composition.

6. A low pour point mineral oil composition comprising wax-containing mineral oil and a wax-containing mineral oils which comprises adding thereto a small quantity of a soap of the tetravalent form of a metal of the titanium subgroup'of Group IV and a carboxylic acid containing more than nine carbon atoms.

11. The method according to claim 10 in which the quantity of the soap is between 0.01% and 1.0% 01' the wax-bearing mineral oil.

12. A low pour point mineral oil composition comprising wax-containing mineral oil and a small quantity of a titanium tetrastearate soap of a carboxylic acid containing more than nine carbon atoms.

- 13. The method of reducing the pour point of wax-containing mineral oils which comprises adding thereto a small quantity of a soap of the tetravalent form of a metal from the group consisting of titanium, hafnium and thorium, and a carboxylic acid containing more than nine carbon atoms. Q

14. The method of reducing the pour point of wax-containing mineral oils which comprises adding thereto a small quantity of a titanic soap of a carboxylic acid containing more than nine carbon atoms.

15. The method according to claim 14 in which the quantity of the soapis between 0.01% and 1.0% of the wax-bearing mineral oil.

16. The method of reducing the pour point of wax-containing mineral oils which comprises adding thereto a small quantity of a thoric soap of a carboxylic acid containing more than nine carbon atoms.

17. The method of reducing the pour point of wax-containing mineral oils which comprises adding thereto a small quantity of a hafnic soap of a carboxylic acid containing more than nine carbon atoms.

18. The method according to claim 12in which the soap contains four acyl side chains;

19. The method according to claim 13 in which the soap contains four acyl side chains.

20. The method of reducing the pour point of wax-containing mineral oils which comprises adding thereto a small quantity of titanium tetrastearate.

FRANZ RUDOLF MOSER. 

